This build error was reported to me off list:
common/callback.c:993:13: error: initializing 'char *' with an expression of type 'const char *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
993 | char *q = strchr (m, ',');
| ^ ~~~~~~~~~~~~~~~
This is because with C23, strchr returns 'const char *' if a 'const
char *' is passed as an argument.
In this case M is 'const char *', so Q should also be 'const char *'.
And indeed, we don't write via Q at any time, so lets make it 'const'.
There should be no user visible changes after this commit.
36a4bbcec4